1. Field of the Invention
The present invention relates to a compressor to compress refrigerant using compression chambers formed within a cylinder block by a rotor and vanes rotating within the cylinder block.
2. Description of Related Art
An air compressor is disclosed in Japanese Patent Application Laid-Open No. 2007-100602 (Patent Document 1). The compressor is a vane-type compressor. Generally in a vane-type compressor, an oil pressure (back pressure) pressured by a discharge pressure is supplied to vane slots provided in a rotor. Vanes in the vane slots are pressed toward an inner surface (cam face) of compression chambers in a cylinder block due to this back pressure. As a result, activation of compression is improved and chattering between the vanes and the cam face is reduced.
In the above air compressor, additional high-pressure supply paths are provided in addition to commonly used back-pressure supply paths. The additional high-pressure supply paths are changed over from the back-pressure supply paths by spring-driven valves to restrict reduction of a chattering prevention function at activation where the discharge pressure (back pressure) is insufficient.
In addition, a vane pump is disclosed in Examined Japanese Utility Model Application Publication No. Hei 8-538 (Patent Document 2). In the vane pump, coil springs are provided for pushing vanes chattering is prevented by the coil springs in addition to the above-mentioned back pressure. In addition, guide pins are inserted in to the coil springs to prevent serpentine flections of the coil springs being compressed. The guide pins are shorter than the coil springs being extended. If the coil springs serpentine when being compressed, reciprocating of the vanes may be inhibited. The guide pins are attached in vane slots with interposing support plates.